System And Method For Displaying Vehicle Efficiency

ABSTRACT

A system and method for determining and displaying an overall efficiency value of a vehicle. The vehicle may include an engine and an electric machine that operates to provide torque to propel the vehicle. In addition, the vehicle may have an electric power source that provides electric power to the electric machine. A controller may determine and transmit the overall efficiency value so that the information display displays the number of efficiency indicators. Also, the number of efficiency indicators displayed may be based on the overall efficiency value.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.12/259,465 filed Oct. 28, 2008, the disclosure of which is herebyincorporated by reference in its entirety.

BACKGROUND

1. Technical Field

One or more embodiments of the present application relate to a systemand method for indicating to a driver the overall efficiency of avehicle.

2. Background Art

Vehicles, whether passenger or commercial, include a number of gauges,indicators, and various other displays to provide the vehicle driverwith information regarding the vehicle and its surroundings. With theadvent of new technologies, such as hybrid electric vehicles (HEVs), hascome a variety of new gauges and information displays that help driversto better learn the operation of these vehicles that utilize newtechnology. For example, many HEVs incorporate gauges that attempt toprovide the driver with information on the various hybrid drivingstates. These gauges indicate to the driver when the vehicle is beingpropelled by the engine alone, the motor alone, or a combination of thetwo. Similarly, a display may indicate when the motor is operating as agenerator, and is recharging an energy storage device, such as abattery.

With regard to HEVs, it is known that some drivers may not be able toachieve desired driving efficiency, in part because of driving habits.In many cases, drivers are willing to modify their behavior, but areunable to translate recommended techniques into real changes in theirdriving habits. Moreover, gauges or displays that fail to continuallyupdate the driver do not allow the driver to adapt their driving habitsso as to achieve the most optimal overall efficiency.

Therefore, a need exists for an information display for a vehicle thatfacilitates efficient operation of the vehicle by indicating to a drivera direct correlation between vehicle operation and overall efficiency.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a schematic representation of a hybrid electric vehicleincluding an information display in accordance with an embodiment of thepresent application;

FIG. 2 a shows in detail the information display depicted in FIG. 1;

FIG. 2 b shows an alternate view of the information display depicted inFIG. 2 a;

FIG. 2 c shows another alternate view of the information displaydepicted in FIG. 2 a;

FIG. 3 is a simplified, exemplary flow chart depicting one or moreembodiments of the present application described herein; and

FIG. 4 is an alternate simplified, exemplary flow chart depicting one ormore embodiments of the present application described herein.

DETAILED DESCRIPTION

FIG. 1 shows a schematic representation of a vehicle 10, which includesan engine 12 and an electric machine, or a generator 14. The engine 12and the generator 14 are connected through a power transfer arrangement,which in this embodiment, is a planetary gear arrangement 16. Of course,other types of power transfer arrangements, including other gear setsand transmissions, may be used to connect the engine 12 to the generator14. The planetary gear arrangement 16 includes a ring gear 18, a carrier20, planet gears 22, and a sun gear 24.

The generator 14 can also output torque to a shaft 26 connected to thesun gear 24. Similarly, the engine 12 outputs torque to a crankshaft 28,which is connected to a shaft 30 through a passive clutch 32. The clutch32 provides protection against over-torque conditions. The shaft 30 isconnected to the carrier 20 of the planetary gear arrangement 16, andthe ring gear 18 is connected to a shaft 34, which is connected to afirst set of vehicle drive wheels, or primary drive wheels 36, through agear set 38.

The vehicle 10 includes a second electric machine, or motor 40, whichcan be used to output torque to a shaft 42 connected to the gear set 38.Other vehicles within the scope of the one or more embodiments of thepresent application may have different electric machine arrangements,such as more or fewer than two electric machines. In the embodimentshown in FIG. 1, the electric machine arrangement (i.e. the motor 40 andthe generator 14) can both be used as motors to output torque.Alternatively, each can also be used as a generator, outputtingelectrical power to a high voltage bus 44 and to an energy storagesystem 46, which includes a battery 48 and a battery control module(BCM) 50.

The battery 48 is a high voltage battery that is capable of outputtingelectrical power to operate the motor 40 and the generator 14. The BCM50 acts as a controller for the battery 48. Other types of energystorage systems can be used with a vehicle, such as the vehicle 10. Forexample, a device such as a capacitor can be used, which, like a highvoltage battery, is capable of both storing and outputting electricalenergy. Alternatively, a device such as a fuel cell may be used inconjunction with a battery and/or capacitor to provide electrical powerfor the vehicle 10.

As shown in FIG. 1, the motor 40, the generator 14, the planetary geararrangement 16, and a portion of the second gear set 38 may generally bereferred to as a transmission 52. To control the engine 12 andcomponents of the transmission 52 (i.e., the generator 14 and motor 40)a vehicle control system, shown generally as controller 54, is provided.Although it is shown as a single controller, it may include multiplecontrollers which may be used to control multiple vehicle systems. Forexample, the controller 54 may be a vehicle system controller/powertraincontrol module (VSC/PCM).

A controller area network (CAN) 56 allows the controller to communicatewith the transmission 52 and the BCM 50. Just as the battery 48 includesa BCM 50, other devices may have their own controllers. For example, anengine control unit (ECU) may communicate with the controller 54 and mayperform control functions on the engine 12. In addition, thetransmission 52 may include a transmission control module (TCM),configured to coordinate control of specific components within thetransmission 52, such as the generator 14 and/or the motor 40. Some orall of these various controllers can make up a control system inaccordance with the present application. Although illustrated anddescribed in the context of the vehicle 10, which is an HEV, it isunderstood that embodiments of the present application may beimplemented on other types of vehicles, such as those powered by anengine or electronic motor alone.

Also shown in FIG. 1 are simplified schematic representations of abraking system 58, an accelerator pedal 60, and an air conditioningsystem 62. The braking system 58 may include such things as a brakepedal, position sensors, pressure sensors, or some combination of thetwo, as well as a mechanical connection to the vehicle wheels, such asthe wheels 36, to effect friction braking. The braking system 58 mayalso include a regenerative braking system, wherein braking energy iscaptured and stored as electrical energy in the battery 48. Similarly,the accelerator pedal 60 may include one or more sensors, which, likethe sensors in the braking system 58, communicate with the controller54.

The air conditioning system 62 also communicates with the controller 54.The on/off status of the air conditioning system can be communicated tothe controller 54, and can be based on, for example, the status of andriver actuated switch, or the automatic control of the air conditioningsystem 62 based on related functions such as window defrost. In additionto the foregoing, the vehicle 10 includes an information display system64, which, as explained in detail below, provides efficiency informationto the driver of the vehicle 10.

FIG. 2 a generally illustrates one embodiment of the information displaysystem 64. The information display system 64 may include an informationdisplay 66 and electronics, including software, which are not shown inFIG. 2 a. The information display 66 may indicate the efficiencyinformation using any number of analog gauges. Alternatively, theinformation display 66 may indicate the efficiency information using aliquid crystal display (LCD), a plasma display, an organic lightemitting display (OLED) or any other display suitable to displayefficiency information.

One or more embodiments of the present application contemplate that theefficiency information indicated to a user may correlate to the user'srecent driving habits of the vehicle 10. More particularly, theinformation display 66 may indicate to a driver an overall efficiency interms of an amount saved by operating the vehicle 10 in a fuel efficientmanner, or in terms of overall energy efficiency.

The overall efficiency may be defined as dollars saved, fuel saved,energy saved, harmful emissions, or the like. By providing efficiencyinformation to the driver, the information display 66 may be used by thedriver to modify operation of the vehicle 10 in order to increase theoverall efficiency of the vehicle 10. FIGS. 2 b and 2 c furtherillustrate the information display 66 as the driver increases theefficiency during operation of the vehicle 10.

The information display 66 may also include a control system, which, forreference purposes, may be the controller 54 described in FIG. 1. Thecontroller 54 may be configured to receive sensed inputs that relate tocurrent operating conditions of the vehicle 10, and the controller 54may provide outputs to the information display system 64 such that theinformation display 66 indicates to the driver a current or recentefficiency of the vehicle 10. According to an embodiment of the presentapplication, the efficiency of the vehicle 10 may be displayed using oneor more efficiency indicators 68.

As illustrated in FIGS. 2 a, 2 b, and 2 c, the driver may be visuallyinformed when particular vehicle operation results in increasedefficiency by increasing the number of efficiency indicators 68displayed. For example, if the vehicle 10 is operated in a relativelyefficient manner, the information display 66 may display more efficiencyindicators 68, thereby informing the driver of the improved vehicleoperation. Conversely, if the vehicle is operated in an inefficientmanner, the information display 66 may reduce the number of efficiencyindicators 68 displayed. As such, the information display system 64 mayaid the driver in modifying operation of the vehicle 10 in order toacquire an optimal efficiency.

While the efficiency indicators 68 illustrated in FIGS. 2 a, 2 b and 2 care represented as leaves, one skilled in the art would understand thatother efficiency indicators may be provided without departing from thescope of the present application. For example, the information display66 may display the efficiency indicators 68 as one or more dollar bills.Similar to the usage of leaves, the quantity of dollar bills displayedmay increase as the driver operates the vehicle in a more efficientmanner. The information display 66 may also use a dollar bill toillustrate efficiency by increasing the numerical value of the dollarbill. Thus, the denomination of the dollar bill may be modified as thevehicle is operated in a more efficient manner.

The information display 66 may also be illustrated in the form of agraph. For example, the information display 66 may be illustrated as abar graph, wherein the efficiency indicators 68 displayed may illustratea segment of the bar graph. As such, when the vehicle 10 is operated inan efficient manner, the number of efficiency indicators 68, orsegments, may increase. Alternatively, when the vehicle 10 is operatedin an inefficient manner, the number of the efficiency indicators 68, orsegments, may decrease.

FIG. 3 illustrates a simplified, exemplary flow diagram 100demonstrating how an overall efficiency of the vehicle 10 may bedetermined. The overall energy efficiency of the vehicle 10 may bedetermined by considering that both the electric machines (generator 14and motor 40) and the engine 12 may be used to power the vehicle 10. Inconsidering both the amount of fuel and electricity consumed by theengine 12 and the electric machines 14, 40, respectively, theinformation display 66 more accurately indicates to the driver theoverall energy efficiency of the vehicle.

One or more embodiments of the present application further contemplatethat the controller 54 may determine the overall energy efficiency as a“short term” energy efficiency value and/or a “long term” energyefficiency value. The “short term” energy efficiency value may becontinually determined over a “short term” time period or distancetraveled value. As such, the information display 66 may inform thedriver as to how the vehicle 10 is being operated over a “short term”time period or a “short term” distance traveled. For example, if the“short term” time period value is five minutes, the “short term” energyefficiency would be determined every five minutes while the vehicle 10is running. Alternatively, if the “short term” distance traveled valueis five miles, the “short term” energy efficiency value would bedetermined every five miles the vehicle 10 travels.

One or more of the present applications contemplate that the “shortterm” time period or distance traveled value may operate as a rollingcalculation. As such, the “short term” energy efficiency may bedetermined based upon a rolling predetermined frequency (e.g., a five orten msec refresh rate). For example, if the “short term” time period isfive minutes and the predetermined frequency is five msecs, the “shortterm” energy efficiency would be determined every five msec. Hence, the“short term” energy efficiency would operate to continually use newinformation to determine the “short term” energy efficiency and theinformation display 66 would display the updated “short term” energyefficiency.

One or more embodiments of the present application contemplates that the“short term” time period or distance traveled value may bepredetermined. Alternatively, the “short term” time period or distancetraveled value may be a user-defined value. The driver may input theuser-defined value using a user interface system and the controller 54may receive and store the user-defined value in memory. The controller54 may then use the user-defined value in order to determine the “shortterm” energy efficiency value.

The “long term” energy efficiency value may be determined from the timethe vehicle 10 is started until a “long term” end time value haselapsed. Generally, the “long term” end time value may be the time whenthe vehicle 10 is turned off. As such, the “long term” energy efficiencyvalue would be determined from the time when the vehicle 10 is turned onuntil the time when the vehicle 10 is turned off. The “long term” energyefficiency value may therefore indicate to a driver the “long term”energy efficiency in terms of a trip or commute.

One or more embodiments of the present application further contemplatesthat the “long term” end time value may be a “long term” time period ora “long term” distance traveled. Thus, the “long term” energy efficiencyvalue may be determined from the time when the vehicle 10 is turned onuntil the “long term” time period elapses or until the “long term”distance traveled is reached. For example, if the “long term” timeperiod is twenty minutes, the “long term” energy efficiency value wouldbe determined over the course of twenty minutes starting from the timewhen the vehicle 10 is turned on. On the other hand, if the “long term”distance traveled value is twenty miles, then the “long term” energyefficiency value would be determined over the course of twenty milesstarting from the time when the vehicle 10 is turned on.

The information display 66 may operate to display either the “shortterm” or “long term” energy efficiency values. Generally, the “shortterm” energy efficiency value may be obtained by the information displaysystem 64 while the vehicle 10 is being operated. In turn, theinformation display system 64 may modify the number of efficiencyindicators 68 displayed by the information display 66 in response to theobtained “short term” energy efficiency value. The controller 54 mayalso continue to obtain new short term” energy efficiency values so thatthe information display 66 continuously updates while the vehicle 10 isbeing operated.

One or more embodiments of the present application contemplate that the“long term” energy efficiency value may typically be transmitted to theinformation display 66 when the vehicle is turned off. For example,while the vehicle 10 is operating, the controller 54 may transmit the“short term” energy efficiency value to the information display 66.Then, upon the vehicle 10 being turned off, the controller 54 maytransmit the “long term” energy efficiency value to the informationdisplay 66. Thus, the information display 66 may display the “shortterm” energy efficiency value while the vehicle 10 is running and the“long term” energy efficiency value while the vehicle is turned off.

However, one or more embodiments of the present application alsocontemplate that the “long term” energy efficiency value may betransmitted to the information display 66 at any time. Furthermore, thecontroller 54 may be preset or the driver may be able to select todisplay the “long term” energy efficiency value. As such, the controller54 may transmit the “long term” energy efficiency value to theinformation display 66 while the vehicle is running and the informationdisplay 66 may modify the number of efficiency indicators 68 in respectto the transmitted “long term” energy efficiency value.

Lastly, the controller 54 may be capable of storing any number ofprevious “long term” energy efficiency values in memory. As such, thedriver may be capable of recalling and displaying previous “long term”energy efficiency values on the information display 66. The driver mayuse the previous “long term” energy efficiency values displayed as a wayto improve how efficiently the vehicle 10 is operated. For example, ifthe driver commutes to work using the same route daily, the driver mayreview the previous weeks “long term” energy efficiency values thatcorrelate to the drivers daily commute. After reviewing the previous“long term” energy efficiency values, the driver may modify theoperation of the vehicle 10 in order to increase the “long term” energyefficiency value during a future daily commute.

With reference back to the FIG. 3, step 110 illustrates that thecontroller 54 may receive a number of sensed or non-sensed vehicleinputs that correspond to current operating conditions or overall energyefficiency of the vehicle 10. For example, the controller 54 may receivea battery voltage value, a battery current value, a fuel flow ratevalue, a distance traveled value, an average speed value, or the like.

Once the sensed or non-sensed vehicle inputs are received, the flowdiagram 100 may proceed to step 120 where the controller 54 may use thesensed and non-sensed vehicle inputs in order to calculate a fuel powervalue. The fuel power value may represent the amount of power consumedby the engine 12 in order to power the vehicle 10. In order to calculatethe fuel power value, the controller 54 may use the following exemplaryequation:

Fuel_Power=Fuel_Flow_Rate*Energy_Density  (1)

where,Fuel_Power is the determined fuel power value;Fuel_Flow_Rate is the received fuel flow rate value that corresponds tothe amount of fuel being injected into the engine 12; andEnergy_Density is a stored energy density value that corresponds to anamount of energy stored in the vehicle 10 per unit mass.

Equation (1) illustrates that the controller 54 may calculate the fuelpower value using a received fuel flow rate value. One or moreembodiments of the present application recognize that the fuel flow ratevalue received by the controller 54 may be the fuel injection flow rateof the engine 12 and may be expressed in terms of pounds per hour(lbs/hr). As such, the fuel flow rate value may correlate to a fuel-airmixture that is injected into the engine 12.

One or more embodiments of the present application also contemplate thatthe energy density value may be required in order to convert the fuelflow rate value into the fuel power value. As such, the controller 54may store in memory a look up table having any number of estimatedenergy density values. The controller 54 may select the estimated energydensity value that most closely corresponds to the fuel used by thevehicle 10. For example, one or more embodiments of the presentapplication may recognize that the vehicle 10 uses a standard unleadedfuel mixture that has an energy density value of approximately 42.7mega-jewel per kilogram (MJ/kg). Thus, the controller 54 may use 42.7MJ/kg as the energy density value in order to determine the fuel powervalue of the vehicle 10.

Once the fuel power value has been determined, the flow diagram 100 mayproceed to step 130. In step 130, the controller 54 may determine abattery power value using the received battery voltage value and batterycurrent value. Typically, the received battery voltage and batterycurrent values indicate the amount of voltage and current consumed bythe vehicle 10. However, one or more embodiments of the presentapplication contemplates that the received battery voltage value andbattery current value may account for the amount of voltage and currentbeing consumed from the battery 48 and supplied to the battery 48 whilethe vehicle 10 is being operated. The battery power value may bedetermined using the following exemplary equation:

Battery_Power=Battery_Voltage*Battery_Current  (2)

where,Battery_Power is the determined battery power value;Battery_Voltage is the received battery voltage value; andBattery_Current is the received battery current value.

Once the battery power value is determined, the flow diagram 100 mayproceed to step 140. In step 140, the controller 54 may use thedetermined fuel power value from Equation (1) and the determined batterypower value from Equation (2) in order to determine a fuel and batteryenergy value. The fuel and battery energy values may represent theamount of energy used by the engine 12 and electric machines 14,40,separately, in order to power the vehicle 10. The fuel energy value maybe determined by the controller 54 using the following exemplaryequation:

$\begin{matrix}{{Fuel\_ Energy} = {\int_{t_{1}}^{t_{2}}{{Fuel\_ Power}\left( {t} \right)}}} & (3)\end{matrix}$

where,Fuel_Energy is the determined fuel energy value of the vehicle 10; andFuel_Power is the fuel power value as determined by Equation (1).The controller 54 may also calculate the battery energy value using thefollowing exemplary equations:

$\begin{matrix}{{Battery\_ Energy} = {\int_{t_{1}}^{t_{2}}{{Battery\_ Power}\left( {t} \right)}}} & (4)\end{matrix}$

where,Battery_Energy is the determined battery energy value of the vehicle 10;andBattery_Power is the battery power value as determined by Equation (2).

One or more embodiments of the present application contemplate that fueland battery energy values are integrated over a power integration period(t₁ to t₂). As such, the controller 54 may use the power integrationperiod (t₁ to t₂) in order to determine the fuel and battery energyvalues.

One or more embodiments of the present application also contemplate thatthe controller 54 may set the power integration period (t₁ to t₂) equalto the “short term” time period. As such, the integration time periodvalue used to calculate the fuel and battery energy values willcorrespond to the “short term” time period. For example, if the “shortterm” time period is set to five minutes, then the power integrationperiod (t₁ to t₂) may be set from t₁ equal to zero to t₂ equal to 5minutes. Alternatively, if the “short term” energy efficiency value isbeing determined using a “short term” distance traveled, the powerintegration period may continue until the “short term” distance traveledis reached.

With reference to the “long term” energy efficiency value, thecontroller 54 may set the start of the power integration period (t₁) asthe period of time when the ignition of the vehicle is started. Thecontroller 54 may also set the end of the power integration period (t₂)as the “long term” end time value. As such, the “long term” energyefficiency value may be determined using a fuel and battery energy valuethat may have a power integration period (t₁ to t₂) equal to the timethe ignition of the vehicle is started until the “long term” end timevalue.

Once the battery and fuel energy values are determined, the flow diagram100 may proceed to step 150 where a vehicle energy value is determined.The controller 54 may calculate the vehicle energy value using thefollowing exemplary equation:

Vehicle_Energy=Fuel_Energy+Battery_Energy  (5)

where,Vehicle_Energy is the determined vehicle energy value;Fuel_Energy is the fuel energy value as determined by Equation (3); andBattery_Energy is the battery energy value as determined by Equation(4).

Once the vehicle energy value is determined, the flow diagram 100 mayproceed to step 160. In step 160, the controller 54 may use the vehicleenergy value in order to calculate an energy used per distance value.The energy used per distance value may be determined by the controller54 using the following exemplary equation:

$\begin{matrix}{{{Energy\_ Used}{\_ Per}{\_ Distance}} = \frac{Vehicle\_ Energy}{Distance\_ Traveled}} & (6)\end{matrix}$

where,Energy_Used_Per_Distance is the determined energy used per distancevalue;Vehicle_Energy is the vehicle energy value as determined by Equation(5); andDistance_Traveled is a distance traveled value.As illustrated in Equation (6), the energy used per distance valuerequires the controller 54 to determine a distance traveled value. Oneor more embodiments of the present application contemplate that thedistance traveled value may be different when the controller isdetermining the “short term” and “long term” energy efficiency values.For example, if the controller 54 is determining the “short term” energyefficiency value, the distance traveled value may be the integral of theaverage vehicle speed over the power integration period (t₁ to t₂) asused in Equations (3) and (4).

On the other hand, if the controller 54 is determining the “long term”energy efficiency value, the distance traveled value may be the totaldistance traveled by the vehicle from the time the vehicle is turned onuntil the “long term” end time value. As stated above, the “long term”end time value may be a specified time period or distance traveledvalue. If the “long term” end time value is a specified time period thenthe distance traveled may be the integral of the average vehicle speedover that specified time period value. However, if the “long term” endtime value is a “long term” distance traveled value, then the distancetraveled value is equal to the “long term” distance traveled value.Lastly, if the controller 54 is determining the “long term” energyefficiency from the time the vehicle 10 is turned on until when thevehicle 10 is turned off, the distance traveled value may be the totaldistance traveled by the vehicle 10 during the period the vehicle 10 isturned on until the vehicle 10 is turned off.

Once the energy used per distance value is determined, the flow diagram100 may proceed to step 170. In step 170, the controller 54 maydetermine the overall energy efficiency value. When determining the“short term” energy efficiency value, the controller 54 may use a filterto average the energy used per distance value. The energy used perdistance value may be averaged using a predetermined or programmabletime period (e.g., a five minute time period) or a specified number ofprevious energy used per distance values (e.g., a buffer of the previousfive energy used per distance values). The controller 54 then may use alook up table that is stored in memory in order to correlate theaveraged energy used per distance value to a “short term” energyefficiency value. Once the energy used per distance traveled value iscorrelated, the controller 54 may transmit the “short term” energyefficiency value to the information display 66. In turn, the informationdisplay 66 may modify the number of efficiency indicators 68 displayedin respect to the transmitted “short term” energy efficiency value.

One or more embodiments of the present application also contemplatesthat the controller 54 may modify the “short term” time period if thevehicle 10 comes to a complete stop but has not been turned off. Thecontroller 54 may modify the “short term” time period because the energyused per distance value may begin to increase thereby correlating into adecreasing “short term” energy efficiency value. As such, the controller54 may be receive a signal when the vehicle 10 has stopped or nearlystopped and the controller 54 may modify the “short term” time period tominimize the impact of stopping the vehicle on the “short term” energyefficiency. For example, during operation of the vehicle 10, the energyused per distance value may typically be averaged over a 100 sec timeperiod. However, if the controller 54 receives a signal that the vehicle10 has stopped, the controller 54 may extend the time period to 2000 secso that the averaged energy used per distance value may not correlateinto a rapidly decreasing “short term” energy efficiency value.

With reference to the “long term” energy efficiency value, thecontroller 54 may determine a “long term” average energy used perdistance value based on a rolling “long term” time period or upon arolling number of previous energy used per distance values (e.g., arolling buffer of the last five energy used per distance values).Alternatively, the controller 54 may determine the “long term” energyefficiency value based upon an averaged “short term” energy efficiencyvalue. For example, the “long term” energy efficiency value may bedetermined by averaging the first “short term” energy efficiency valuethat is determined after the engine 12 is turned on, with eachconsecutive “short term” energy efficiency value determined until the“long term” end time value is reached.

Once the “long term” end time value is reached, the controller 54 maycorrelate the averaged energy used per distance value using the look uptable in order to determine the “long term” energy efficiency value. Thecontroller 54 may then transmit the “long term” energy efficiency valueto the information display 66. The information display 66 may modify thenumber of efficiency indicators 68 displayed in respect to thetransmitted “long term” energy efficiency value.

With reference back to the illustrations, FIG. 4 is an alternative flowdiagram 200 demonstrating how the efficiency of the vehicle 10 may bedetermined. In particular, at step 210 any number of sensed ornon-sensed vehicle inputs that correspond to current operatingconditions or efficiency of the vehicle 10 may be received. The receivedinputs may be used by the controller 54 to calculate the efficiency ofthe vehicle 10 in terms of a monetary amount saved.

Once the sensed and non-sensed vehicle inputs are received, the flowdiagram 200 may proceed to step 220. In step 220, the controller 54 mayuse the sensed and non-sensed vehicle inputs in order to determine anamount of fuel consumed by the vehicle 10 while the vehicle 10 travels aspecified distance. In short, the controller 54 may use the sensed andnon-sensed vehicle inputs in order to determine a fuel economy of thevehicle 10. Once the fuel economy of the vehicle 10 is determined, theflow diagram 200 may proceed to step 230.

In step 230, a monetary amount saved per distance value may bedetermined. The monetary amount saved per distance value may bedetermined using the following exemplary equation:

$\begin{matrix}{{{Amount\_ Saved}{\_ Per}{\_ Distance}} = {\left( {\frac{1({gallon})}{{Compare\_ FE}({distance})} - \frac{1({gallon})}{{Real\_ FE}({distance})}} \right)*{Fuel\_ Price}\mspace{11mu} \left( \frac{\$}{gallon} \right)}} & (7)\end{matrix}$

where,Amount_Saved_Per_Distance is the determined monetary amount saved perdistance value;Real_FE is a determined fuel efficiency of the vehicle 10;Compare_FE is a comparison fuel economy value; andFuel_Price is a price per quantity of fuel.

As Equation (7) illustrates, the comparison value (Compare_FE) and thefuel price value (Fuel_Price) cannot be determined using sensed vehicledata or other vehicle fuel efficiency data. As such, one or moreembodiments of the present application contemplates that theseparameters may be received from any number of external sources. Forexample, the comparison value and the fuel price values may be presetand stored within the memory of the controller 54.

One or more embodiments of the present application contemplate that thestored comparison value may represent the fuel economy of a secondvehicle that has similar characteristics to that of the vehicle 10. Forexample, if the vehicle 10 is a Ford Escape hybrid, then the comparisonvalue may be a non-hybrid Ford Escape. Alternatively, if the vehicle isa Ford Escape Hybrid, then the comparison value may be a hybrid ornon-hybrid small to mid-size sports utility vehicle that is produced byanother car manufacturer.

The comparison value and the fuel price value may also be entered intothe memory or selected from memory by the driver using a graphical userinterface or through a voice activation system such as the Ford Syncvoice activation system. By allowing the driver the ability to manuallyor verbally select or input the fuel price and the comparison value, thedriver may be notified how efficiently the vehicle 10 is being operatedin comparison to a known second vehicle or a known fuel price. Forexample, the driver may be able to select a previously owned vehicle asthe comparison value and the information display 64 may display theefficiency of the vehicle 10 in comparison to the previously ownedvehicle. In addition, the driver may be able to set the fuel price valueand determine how efficient the vehicle 10 is being operated at varyingfuel prices.

One or more embodiments of the present application also contemplate thatthe fuel price value may be updated using a wireless system. Somenon-limiting examples of the wireless system may include WiFi,Bluetooth, or a cellular source. The controller 54 may use the receivedfuel price value to update and accurately display the amount saved tothe driver on the information display 64. As such, the controller 54 maycontinually update and modify the information display 64 so as toaccurately display how efficiently the driver is operating the vehicle10.

Once the controller 54 calculates the monetary amount saved per distancevalue, the flow diagram 200 proceeds to step 240. In step 240, a currenttotal monetary amount saved value is determined using the followingequation:

Total_Amount_Saved=Amount_Saved_Per_Distance*Reset_Value  (8)

where,Total_Amount_Saved is the current total monetary amount saved value;Amount_Saved_Per_Distance is the monetary amount saved per distancevalue as determined using Equation (7); andReset_Value is an event triggered reset value that is input to thecontroller 54 by the driver.

The reset value (Reset_Value) may be a rolling distance value that maybe reset in accordance with a driver defined event. For example, thedriver defined event that resets the total monetary amount saved valuemay be based upon a tank of fuel, a trip, or a period of time (e.g., aweek, month, year). The reset value may also be programmable by thedriver so that the value resets upon reaching a particular distance oramount of fuel consumed. As such, the reset value may automaticallyreset once the driver programmed event is reached.

The controller 54 may be capable of storing multiple reset values thatare used to calculate multiple total monetary amount saved values. Thecontroller 54 may allow the driver to store and display one or more ofthe multiple total monetary amount saved values on the informationdisplay 66. Thus, the driver would be capable of selecting anddisplaying the total monetary amount saved value based upon the life ofthe vehicle 10, a trip counter, when the driver last refueled thevehicle 10, or the like.

One or more embodiments of the present application also contemplate thatthe controller 54 may be capable of storing multiple total monetaryamount saved values. By storing multiple total monetary amount savedvalues, any number of vehicle drivers may be capable of storing a driverunique total monetary amount saved value. Each driver may then be ableto select and display the driver unique total monetary amount savedvalue that represents the efficiency of that particular driver's vehicleoperation. Hence, each driver may be capable of comparing their uniquetotal monetary amount saved value with respect to other driver uniquetotal monetary amount saved values in order to determine how to modifytheir vehicle operation thereby increasing efficiency.

Once the total monetary amount saved value is determined, the flowdiagram 200 may proceed to step 250. In step 250, the controller 54 maydetermine if the total monetary amount saved value is greater than apreviously stored total monetary amount saved value. Depending upon thedetermination of step 250, the controller 54 modifies the informationdisplay 66 so as to increase the number of efficiency indicators 68, asillustrated in step 260, or decrease the number of efficiency indicators68, as illustrated in step 270. For example, if the total monetaryamount saved determined at step 240 is greater than the previouslystored total monetary amount saved value, then the number of efficiencyindicators 68 may increase (step 260). If however, the total monetaryamount saved value is less than the previously stored total monetaryamount saved value, then the number of efficiency indicators 68 maydecrease (step 270).

For example, suppose:

Real_FE=32 MPG;

Compare_FE=22 MPG; and

Fuel_Price=$3.50 per gallon;

then,

${{{Amount\_ Saved}{\_ Per}{\_ Distance}} = {\left( {\frac{1}{22} - \frac{1}{32}} \right)*3.5}};{and}$Amount_Saved_Per_Distance = $.0497  per  mile.

With reference to the above example, if the reset value is set to 100miles, then the controller 54 would calculate that the total monetaryamount saved value to be $4.97. If the controller 54 had determined aprevious total monetary amount saved value to be $4.50, then thecontroller 54 would modify the information display 66 to illustrate moreefficiency indicators 68, as shown in step 260.

Conversely, if the controller 54 had determined the previous totalmonetary amount saved value to be $5.03, then the controller 54 wouldmodify the information display 66 to illustrate less efficiencyindicators 68, as shown in step 270. Once the information display 66 ismodified to illustrate a representative amount of efficiency indicators68, the flow diagram 200 may proceed to step 180 where the controller 54stores the current total monetary amount saved value as the previoustotal monetary amount saved value.

Both flow diagram 100 and flow diagram 200 operate so as to consistentlyupdate the information display 66. In turn, the driver may modifyvehicle operation so that the number of efficiency indicators 68indicated upon the information display 66 increases. Thus, as the driverattempts to increase the number of efficiency indicators 66, the driverlearns how to operate the vehicle in the most energy efficient manner.

It should be noted that the methods of FIGS. 3-4 as described herein areexemplary only, and that the functions or steps of the methods could beundertaken other than in the order described and/or simultaneously asmay be desired, permitted and/or possible.

While the best mode for carrying out the invention has been described indetail, those familiar with the art to which this invention relates willrecognize various alternative designs and embodiments for practicing theinvention as defined by the following claims.

1. An information display system for a vehicle including an electricmachine operable to provide torque to propel the vehicle, the vehiclefurther including an electric power source configured to provideelectric power to the electric machine, the information display systemcomprising: an information display configured to display a number ofefficiency indicators; and a controller being configured to receiveinformation related to an amount of electrical energy used in order topropel the vehicle, the controller further being configured to determinean energy efficiency value based upon the amount of electrical energyused and transmit the energy efficiency value so that the informationdisplay displays the number of efficiency indicators based upon theenergy efficiency value.
 2. The information display system of claim 1,wherein the controller is further configured to receive informationrelated to a specified time period, the controller determining theenergy efficiency value from a time when the vehicle is turned on untilthe specified time period has elapsed.
 3. The information display systemof claim 2, wherein the controller is further configured to receiveinformation related to a predetermined distance traveled, the controllerfurther being configured to determine the energy efficiency value from atime when the vehicle is turned on until the predetermined distancetraveled has been reached.
 4. The information display system of claim 3,wherein the controller is further configured to determine the energyefficiency value from a time when the vehicle is turned on until thetime the vehicle is turned off.
 5. The information display system ofclaim 3, further comprising a driver interface system, the driverinterface system being configured to receive the specified time periodand predetermined distance traveled, and the driver interface systemfurther being configured to transmit the specified time period andpredetermined distance traveled to the controller.
 6. The informationdisplay system of claim 3, further comprising a memory used to store thepredetermined time period and the predetermined distance, and thecontroller further being configured to retrieve the predetermined timeperiod and the predetermined distance from the memory.
 7. Theinformation display system of claim 1, wherein the controller is furtherconfigured to receive information related to a specified time period,and the controller further being configured to determine the energyefficiency value from a time after the vehicle is turned on until thespecified time has elapsed.
 8. The information display system of claim1, wherein the controller is further configured to receive informationrelated to a predetermined distance, and the controller further beingconfigured to determine the overall energy efficiency value from a timeafter the vehicle is turned on until a predetermined distance has beentraveled by the vehicle.
 9. A method for displaying efficiencyinformation about a vehicle using an information display system, thevehicle including an electric machine operable to provide torque topropel the vehicle, the vehicle further including an electric powersource configured to provide electric power to the electric machine, themethod comprising: receiving information related to an amount ofelectrical energy used in order to propel the vehicle; determining anenergy efficiency value of the vehicle using the electrical energy usedinformation; transmitting the energy efficiency value to an informationdisplay; displaying a number of efficiency indicators on the informationdisplay based on the energy efficiency value.
 10. The method of claim 9,wherein the step of receiving information related to an amount ofelectrical energy used in order to propel the vehicle further comprisesreceiving information related to a battery voltage and a batterycurrent, and the step of determining an energy efficiency value of thevehicle using the amount of electrical energy used information furthercomprises determining a battery power value using the received batteryvoltage and battery current information.
 11. The method of claim 10, thestep of determining an energy efficiency value of the vehicle using theamount of electrical energy used information further comprisesdetermining a battery energy value using the determined battery powervalue.
 12. The method of claim 11, wherein the step of determining anenergy efficiency value of the vehicle using the amount electricalenergy used information further comprises determining a vehicle energyvalue using the battery energy value.
 13. The method of claim 12,wherein the step of determining an energy efficiency value of thevehicle using the amount of electrical energy used information furthercomprises determining an energy used per distance value using thevehicle energy value and the distance traveled value.
 14. The method ofclaim 13, wherein the step of determining an energy efficiency value ofthe vehicle using the amount of electrical energy used informationfurther comprises determining the overall energy efficiency value byaveraging any number of previous energy used per distance values. 15.The method of claim 14, wherein the step of determining the overallenergy efficiency value by averaging any number of previous energy usedper distance values comprises determining the overall energy efficiencywhen the speed of the vehicle is below a speed threshold value andincreasing the averaged number of previous energy used per distancevalues.
 16. The method of claim 15 further comprising storing in amemory the average overall energy efficiency value, and the step oftransmitting the energy efficiency value to an information displaycomprises transmitting the average overall energy efficiency value tothe information display.